• Title/Summary/Keyword: Dome Part

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Automatic detection of the optimal ejecting direction based on a discrete Gauss map

  • Inui, Masatomo;Kamei, Hidekazu;Umezu, Nobuyuki
    • Journal of Computational Design and Engineering
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    • v.1 no.1
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    • pp.48-54
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    • 2014
  • In this paper, the authors propose a system for assisting mold designers of plastic parts. With a CAD model of a part, the system automatically determines the optimal ejecting direction of the part with minimum undercuts. Since plastic parts are generally very thin, many rib features are placed on the inner side of the part to give sufficient structural strength. Our system extracts the rib features from the CAD model of the part, and determines the possible ejecting directions based on the geometric properties of the features. The system then selects the optimal direction with minimum undercuts. Possible ejecting directions are represented as discrete points on a Gauss map. Our new point distribution method for the Gauss map is based on the concept of the architectural geodesic dome. A hierarchical structure is also introduced in the point distribution, with a higher level "rough" Gauss map with rather sparse point distribution and another lower level "fine" Gauss map with much denser point distribution. A system is implemented and computational experiments are performed. Our system requires less than 10 seconds to determine the optimal ejecting direction of a CAD model with more than 1 million polygons.

Prediction of Reservoir Properties Using Extended Elastic Impedance Inversion (확장 탄성 임피던스 역산을 이용한 저류층 물성 예측)

  • Kim, Hyeonju;Lee, Gwang H.;Moon, Seonghoon
    • Economic and Environmental Geology
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    • v.48 no.2
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    • pp.115-130
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    • 2015
  • Extended elastic impedance (EEI) is an extension of elastic impedance (EI) which is a generalization of acoustic impedance (AI) for nonzero angles of incidence and can be tuned to be proportional to reservoir properties. In this study, we evaluated EEI inversion by estimating the P-($V_p$) and S-wave velocities ($V_s$), P-wave to S-wave velocity ratio ($V_p/V_s$), and Poisson's ratio of the Second Wall Creek Sand of the Teapot Dome field, Wyoming, USA. We also applied the EEI inversion technique to estimate porosity, gamma-ray values, and density of the Second Wall Creek Sand. Data used in the study include 3-D pre-stack seismic data from the southern part of the field and four wells, selected from a large well database. The $V_s$ logs at the wells were constructed from the $V_p$ logs using the empirical relationships. The percent prediction errors for the four velocity properties are less than about 5% except for Poisson's ratio at one well, supporting that the EEI inversion can be used in the prediction of rock properties. However, the results from the EEI inversion analysis of porosity, gamma-ray values, and density at the wells were unsatisfactory and thus these properties, which are not directly computed from velocities, may not be suitable for EEI inversion.

A Preliminary Study on the Exhumation Mechanism of the Paleozoic Gwangcheon Gneiss in the Southwestern Margin of the Gyeonggi Massif (경기육괴 남서 연변부에 발달하는 고생대 광천편마암의 노출기작에 대한 예비 연구)

  • Park, Seung-Ik
    • Economic and Environmental Geology
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    • v.50 no.6
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    • pp.525-535
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    • 2017
  • Exhumation mechanism of migmatite in orogenic belts provides insights into thermo-mechanical evolution of lithosphere in association with orogeny. This study deals with kinematics of structures in and around the Gwangcheon Gneiss, as a preliminary study on exhumation mechanism, which is a main constituent of a domal structure (viz., Oseosan Dome) in the Hongseong area, southwestern margin of the Gyeonggi massif. Geological structures in the Gwangcheon Gneiss, which mainly comprises southern and northwestern part of the Oseosan Dome, generally have kinematic component of top-outward shear. This feature is likely to represent diapiric dome-up movement. In addition, a high strain zone, by which the tectonic domain involving the Gwangcheon Gneiss is bounded on the west, show structural features with normal sense of shear component. Taking available (thermo)chronological data into account, it is interpreted that activation of the high strain zone and exhumation of the Gwangcheon Gneiss occurred during Late Triassic, when the Gyeonggi massif was widely affected by post-collisional processes. It means that the Gwangcheon Gneiss was diapirically moved up and exhumed in the footwall of extensional high strain zone in association with Triassic post-collisional processes.

A Study on the Behavior & Buckling Characteristics of Single-Layer Latticed Domes in the Erection Process (단층 래티스 돔의 Erection 중 거동 및 좌굴 특성)

  • Jung, Hwan-Mok;Kim, Cheol-Hwan;Hwang, Dong-Gyu
    • Journal of Korean Association for Spatial Structures
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    • v.8 no.3
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    • pp.45-51
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    • 2008
  • A single layer-latticed dome is advantageous for large span structures because it is very stiff despite the light weight of the structure itself. However, this structure becomes easily unstable during erection due to its large size. The Block method is popular with the large span structures. A partial block of the dome is fabricated on the ground and lifted by crane to a designated location of structures. The lifting point selection is very important to create a stable erection and to avoid buckling of members during the erection. The purpose of this study is to analyze the structural behaviors and buckling characteristics according to the lifting point of single-layer latticed domes with triangle network in order to take materials about the safe and economic erection. The conclusions are obtained as follow. 1) The buckling strength of the block part varies with the location of lifting points when it is erected. In case, the height of the dome is lower, the effort of buckling strength of the structure is higher. 2) In buckling strength, the effect of the lifting rope length is smaller than it of the lifting points change.

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Stress Distribution Analysis for High Pressure CNG Pressure Vessel Using FEM (유한요소법을 이용한 고압 CNG압력용기 응력분포 해석)

  • Choi, Sang In;Kim, Young Chul;Kim, Myung Soo;Baek, Tae Hyun
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.7 no.2
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    • pp.427-435
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    • 2017
  • Most of the domestic city buses are equipped with the pressure vessels subjected to internal pressure applied by compressed natural gas. Pressure vessels subjected to internal pressure are used in various forms and purposes. Fuel is explosive and has flammable high pressure. The damage of the pressure vessel causes many property damage and loss of life. Safe design for pressure vessel is always necessary. Due to these reasons, many studies using finite element analysis have been conducted. In this paper, the stresses of cylindrical vessel and spherical dome were analyzed using ANSYS, a finite element analysis software. In order to verify the validity of the analysis, a model with a perfectly spherical shape of the dome was designed and observed. Based on the ASME standard in used, stress distribution was also analyzed for models designed with compressed natural gas(CNG). The FEM analysis software agreed with the theory when the dome shape was perfectly spherical. The model designed based on the ASME specification theory, stress concentration occurred in the knuckle part.

The Formation of the Cenozoic Volcanic Edifice in the Goseong-Ganseong Area, Gangwondo, Korea (강원도 고성-간성일대의 신생대 화산체의 형성과정)

  • Kim, Hwa Sung;Kil, Youngwoo;Lee, Moon Won
    • Journal of the Korean earth science society
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    • v.33 no.7
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    • pp.627-636
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    • 2012
  • In the Obongri-Goseong area of Gangwondo, South Korea, there are six densely distributed volcanic edifices i.e., Duibaejae, Oeumsan, Galmibong, 249 m height, 166 m height, and 102 m height, and two other volcanic edifices including Goseongsan and Unbongsan volcanic edifice that are separately located from a distance. A previously undiscovered 249m volcanic edifice in Obongri was found in this investigation, and the six volcanic edifices distributed in Obongri will be referred to as the Obongri volcanic edifice group. Volcanic edifices in this area were interpreted by other researchers as being volcanic plug, plug dome, and cylindrical volcanic pipe type edifices. The aim of this study is to investigate the aspect of volcanic activity in the Obongri-Goseong area and the formation of volcanic edifices by examining of the shape of volcanic edifices, stratigraphy, and characterization of volcanic products. All the volcanic edifices in the area are composed of basaltic rocks on the Mesozoic granite basement, and the prevalence of the dome shape increased towards the upper part of the mountain. Three volcanic edifices (Duibaejae, 166 m height, 102 m height) include intercalated pyroclastic deposits between the basaltic rocks and the basement. The pyroclastic deposit in the Duibaejae volcanic edifice is composed of quartz, feldspar, granite fragments originated from the basement, and scoria fragments originated from the volcanic eruption. In addition to angular olivine, plagioclase, and pyroxene xenocrysts, all the basaltic rocks contained mantle xenolith, gabbroic xenolith originated from the lower crust, and granitic xenolith originated from the basement. This fact indicates that magma rapidly rose to the surface and that the volcanic activity was explosive. It is also interpreted that, as the basaltic magma became highly viscous due to the large amount of xenocrysts, the erupted magma formed a dome structure on the surface. The original dome structure was then severely eroded out leaving a plug dome formation on the basement.

A Study on Impression Formation According to Design Elements of Wedding Dresses and Perceiver's Gender(Part I) -Emphasis on Silhouettes and Necklines of Wedding Dresses- (웨딩드레스의 디자인 요소와 지각자 성별에 따른 인상형성 연구(제1보) -실루엣과 네크라인을 중심으로-)

  • 이미연;이명희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.24 no.5
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    • pp.724-735
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    • 2000
  • The objectives of this study were to identify the dimensional structure of female impression formation based on silhouettes and necklines of wedding dresses, and to analyze the effect of silhouettes, necklines, and perceiver's gender on impression formation. The experimental design was 3$\times$6$\times$2 (silhouettes$\times$necklines$\times$gender) factorial design by 3 independent variables. Samples were 432 males and females. Four factors derived to account for the dimensions of impression formation. These were attractiveness, neatness, feminity, and prettiness. Dome silhouette had a positive effect on impression of attractiveness. Bell silhouette increased the impression of femininity and prettiness. Tubular silhouette had a negative effect on the impressions of attractiveness, femininity, and prettiness. Neckline had a significant effect on impression of attractiveness and negative on prettiness. Sweet-heart neckline has a positive effect on impression of attractiveness and negative on prettiness. Off-shoulder neckline increased the impression of prettiness. Round neckline decreased the impression of attractiveness. On the interaction effect according to the neckline and perceiver's gender, the men perceived high-necklines to be more feminine than did women, while the women perceived off-shoulder necklines to be more feminine than did men. There was interaction effect between silhouette and neckline on prettiness. In dome silhouette, heart-shape neckline was perceived to be prettier than the others, while in bell silhouette, off-shoulder neckline was perceived as prettier than the others.

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Evaluation of the Structural Safety of a Vessel with Different Material(Cr-13)-Supplemented Screw Thread (이종재료가 보충된 나사산을 갖는 용기의 구조안전성 평가)

  • Choi, Yong Hoon;Bae, Jun Ho;Kim, Chul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.4
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    • pp.375-382
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    • 2015
  • The dome and neck part of a vessel is generally formed by a hot spinning process with a seamless tube. However, as studies on and design data from the hot spinning process are insufficient, this process has been performed based on trial and error and the experiences of field engineers. Changes in the inner diameter from the bottom to the top of the neck have occurred mainly because of the characteristics of the hot spinning process due to the high-speed rotation of the rollers. In this study, a theoretical and finite element analysis of the vessel is conducted with different material(Cr-13)-supplemented screw threads for tapping and to reduce shape errors. Based on the results, tne structural safety under the operating conditions is evaluated.

A scanning electron microscope study on the tegument of Proalayioides kobauushii Park, 1940 (Trematoda) (Proalarioides kobayashii Park, 1940의 표피 미세구조)

  • Ju, Jong-Pil;Im, Il-Seong;Hwang, In-Dam
    • Parasites, Hosts and Diseases
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    • v.29 no.2
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    • pp.173-180
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    • 1991
  • A SEM study was performed on the surface of adult P. habayashii Park, 1940, recovered from the snake, Elaphe rufodorsata. The anterior part of the worms was cup-shape and equipped with oral, ventral suckers, pseudosuckers, and tribocytic organ, and the posterior one was finger-like and round-ended, The tegument of the anterior body was covered with 3~4 pointed small spines on the midventral surface and 1~2 pointed ones on the lateral surface. Sensory papillae such as type II, dome-shape ones, and papillae with an opening were distributed over the ventral surface of the anterior portion. The round tribocytic organ was bearing small stout spines laterally, whereas the surface Which comes in contact with the host tissues consisted of numerous long fibrillar fibers. The lip of the oral sucker contained type II papillae. Lateral margin of the anterior body revealed type III papillae.

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A Study on the facade Expression of the Modern Western Style Architecture in Seoul (서울시 근대 양식건축 파사드의 표현 특성에 관한 연구)

  • Lee, Wan-Geon;Jung, Rye-Hwa
    • Korean Institute of Interior Design Journal
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    • v.18 no.2
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    • pp.16-24
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    • 2009
  • Urban is made over a long period of time. In the process, architecture involves design characteristics of age and place. In the case of modem western style architecture, just depend on the economic logic, they are continuously threatened during urban changes. Therefore, the purpose of this paper is to recognize modern western style architecture as valuable things, which represents color of urban, and to seek how it can be reused. This is a process in order to find a new method for conservation and reuse of modern western style architecture. The result are as followings. Modern western style architecture must be recognized as resource, which expresses identity of urban, and found a method for conservation and reuse of facade at least. So we need to search design characteristics of facade. It has been analyzed that assigned modem western style architecture in seoul can be divided into 6 groups. Each group has individual characteristics of facade expression, which is 'dormer', 'vent', 'balustrade', 'cornice', 'dome', 'tower', etc in top part, and 'the shape of window and door', 'the element of ornament', 'finish', etc in middle part.